ARCed.UI.DockPanel.UpdateWindowRegion_ClipContent C# (CSharp) Method

        private void UpdateWindowRegion_ClipContent()
        {
            int count = 0;
            foreach (DockPane pane in this.Panes)
            {
                if (!pane.Visible || pane.DockState != DockState.Document)
                    continue;

                count++;
            }

            if (count == 0)
            {
                this.SetRegion(null);
                return;
            }

            var rects = new Rectangle[count];
            int i = 0;
            foreach (DockPane pane in this.Panes)
            {
                if (!pane.Visible || pane.DockState != DockState.Document)
                    continue;

                rects[i] = RectangleToClient(pane.RectangleToScreen(pane.ContentRectangle));
                i++;
            }

            this.SetRegion(rects);
        }